Cefaxon is indicated for the treatment of the following infections in adults and children including term neonates (from birth):

• Bacterial Meningitis
• Community acquired pneumonia
• Hospital acquired pneumonia
• Acute otitis media
• Intra-abdominal infections
• Complicated urinary tract infections (including pyelonephritis)
• Infections of bones and joints
• Complicated skin and soft tissue infections
• Gonorrhoea
• Syphilis
• Bacterial endocarditis

 

Cefaxon may be used:

• For treatment of acute exacerbations of chronic obstructive pulmonary disease in adults
• For treatment of disseminated Lyme borreliosis (early (stage II) and late (stage III)) in adults and children including neonates from 15 days of age
• For Pre-operative prophylaxis of surgical site infections
• In the management of neutropenic patients with fever that is suspected to be due to a bacterial infection
• In the treatment of patients with bacteraemia that occurs in association with, or is suspected to be associated with, any of the infections listed above

 

Cefaxon should be co-administered with other antibacterial agents whenever the possible range of causative bacteria would not fall within its spectrum (see section 4.4).

 

Consideration should be given to official guidelines on the appropriate use of antibacterial agents.

Posology

The dose depends on the severity, susceptibility, site and type of infection and on the age and hepato-renal function of the patient.

 

The doses recommended in the tables below are the generally recommended doses in these indications. In particularly severe cases, doses at the higher end of the recommended range should be considered.

 

Adults and children over 12 years of age (≥ 50 kg)

Ceftriaxone Dosage*	Treatment frequency**	Indications
1000-2000 mg	Once daily	Community acquired pneumonia
		Acute exacerbations of chronic obstructive pulmonary disease
		Intra-abdominal infections
		Complicated urinary tract infections (including pyelonephritis)
2000 mg	Once daily	Hospital acquired pneumonia
		Complicated skin and soft tissue infections
		Infections of bones and joints
2000-4000 mg	Once daily	Management of neutropenic patients with fever that is suspected to be due to a bacterial infection
		Bacterial endocarditis
		Bacterial meningitis

* In documented bacteraemia, the higher end of the recommended dose range should be considered.

** Twice daily (12 hourly) administration may be considered where doses greater than 2000 mg daily are administered.

 

Indications for adults and children over 12 years of age (≥ 50 kg) that require specific dosage schedules:

Acute otitis media

A single intramuscular dose of ceftriaxone 1000-2000 mg can be given.

 

Limited data suggest that in cases where the patient is severely ill or previous therapy has failed, ceftriaxone may be effective when given as an intramuscular dose of 1000-2000 mg daily for 3 days.

 

Pre-operative prophylaxis of surgical site infections

2000 mg as a single pre-operative dose.

 

Gonorrhoea

500 mg as a single intramuscular dose.

 

Syphilis

The generally recommended doses are 500 mg-1000 mg once daily increased to 2000 mg once daily for neurosyphilis for 10-14 days. The dose recommendations in syphilis, including neurosyphilis, are based on limited data. National or local guidance should be taken into consideration.

 

Disseminated Lyme borreliosis (early [Stage II] and late [Stage III])

2000 mg once daily for 14-21 days. The recommended treatment durations vary and national or local guidelines should be taken into consideration.

 

Paediatric population

Neonates, infants and children 15 days to 12 years of age (< 50 kg)

For children with bodyweight of 50 kg or more, the usual adult dosage should be given.

Ceftriaxone dosage*	Treatment frequency**	Indications
50-80 mg/kg	Once daily	Intra-abdominal infections
		Complicated urinary tract infections (including pyelonephritis)
		Community acquired pneumonia
		Hospital acquired pneumonia
50-100 mg/kg (Max 4000 mg)	Once daily	Complicated skin and soft tissue infections
		Infections of bones and joints
		Management of neutropenic patients with fever that is suspected to be due to a bacterial infection
80-100 mg/kg (max 4000 mg)	Once daily	Bacterial meningitis
100 mg/kg (max 4000 mg)	Once daily	Bacterial endocarditis

* In documented bacteraemia, the higher end of the recommended dose range should be considered.

** Twice daily (12 hourly) administration may be considered where doses greater than 2000 mg daily are administered.

 

Indications for infants and children 15 days to 12 years (< 50 kg) that require specific dosage schedules:

 

Acute otitis media

For initial treatment of acute otitis media, a single intramuscular dose of Cefaxon 50 mg/kg can be given. Limited data suggest that in cases where the child is severely ill or initial therapy has failed, Cefaxon may be effective when given as an intramuscular dose of 50 mg/kg daily for 3 days.

 

Pre-operative prophylaxis of surgical site infections

50-80 mg/kg as a single pre-operative dose.

 

Syphilis

The generally recommended doses are 75-100 mg/kg (max 4000 mg) once daily for 10-14 days. The dose recommendations in syphilis, including neurosyphilis, are based on very limited data. National or local guidance should be taken into consideration.

 

Disseminated Lyme borreliosis (early [Stage II] and late [Stage III])

50–80 mg/kg once daily for 14-21 days. The recommended treatment durations vary and national or local guidelines should be taken into consideration.

 

Neonates 0-14 days

Ceftriaxone is contraindicated in premature neonates up to a postmenstrual age of 41 weeks (gestational age + chronological age).

Ceftriaxone dosage*	Treatment frequency	Indications
20-50 mg/kg	Once daily	Intra-abdominal infections
		Complicated skin and soft tissue infections
		Complicated urinary tract infections (including pyelonephritis)
		Community acquired pneumonia
		Hospital acquired pneumonia
		Infections of bones and joints
		Management of neutropenic patients with fever that is suspected to be due to a bacterial infection
50 mg/kg	Once daily	Bacterial meningitis
		Bacterial endocarditis

* In documented bacteraemia, the higher end of the recommended dose range should be considered.

A maximum daily dose of 50 mg/kg should not be exceeded.

 

Indications for infants and children 15 days to 12 years (< 50 kg) that require specific dosage schedules:

Acute otitis media

For initial treatment of acute otitis media, a single intramuscular dose of Cefaxon 50 mg/kg can be given.

 

Pre-operative prophylaxis of surgical site infections

20-50 mg/kg as a single pre-operative dose.

 

Syphilis

The generally recommended dose is 50 mg/kg once daily for 10-14 days. The dose recommendations in syphilis, including neurosyphilis, are based on very limited data. National or local guidance should be taken into consideration.

 

Duration of therapy

The duration of therapy varies according to the course of the disease. As with antibiotic therapy in general, administration of Cefaxon should be continued for 48 - 72 hours after the patient has become afebrile or evidence of bacterial eradication has been achieved.

 

Older people

The dosages recommended for adults require no modification in older people provided that renal and hepatic function is satisfactory.

 

Patients with hepatic impairment

Available data do not indicate the need for dose adjustment in mild or moderate liver function impairment provided renal function is not impaired.

 

There are no study data in patients with severe hepatic impairment (see section 5.2).

 

Patients with renal impairment

In patients with impaired renal function, there is no need to reduce the dosage of Cefaxon provided hepatic function is not impaired. Only in cases of preterminal renal failure (creatinine clearance < 10 ml/min) should the Cefaxon dosage not exceed 2000 mg daily.

 

In patients undergoing dialysis no additional supplementary dosing is required following the dialysis.  

 

Ceftriaxone is not removed by peritoneal- or haemodialysis. Close clinical monitoring for safety and efficacy is advised.

 

Patients with severe hepatic and renal impairment

In patients with both severe renal and hepatic dysfunction, close clinical monitoring for safety and efficacy is advised.

 

Method of administration

Intramuscular administration

Cefaxon can be administered by deep intramuscular injection. Intramuscular injections should be injected well within the bulk of a relatively large muscle and not more than 1000 mg should be injected at one site.

 

As the solvent used is lidocaine, the resulting solution should never be administered intravenously (see section 4.3). The information in the Summary of Product Characteristics of lidocaine should be considered.

 

Intravenous administration

Intramuscular administration should be considered when the intravenous route is not possible or less appropriate for the patient. For doses greater than 2000 mg intravenous administration should be used.

 

For pre-operative prophylaxis of surgical site infections, Cefaxon should be administered 30-90 minutes prior to surgery.

 

For instructions on reconstitution of the medicinal product before administration, see section 6.6.

Hypersensitivity to ceftriaxone or to any other cephalosporin. History of severe hypersensitivity (e.g. anaphylactic reaction) to any other type of beta-lactam antibacterial agent (penicillins, monobactams and carbapenems). Cefaxon is contraindicated in: • Premature neonates up to a postmenstrual age of 41 weeks (gestational age + chronological age)* • Full-term neonates (up to 28 days of age): - With hyperbilirubinaemia, jaundice, or who are hypoalbuminaemic or acidotic because these are conditions in which bilirubin binding is likely to be impaired* * In vitro studies have shown that ceftriaxone can displace bilirubin from its serum albumin binding sites leading to a possible risk of bilirubin encephalopathy in these patients. Contraindications to lidocaine must be excluded before intramuscular injection of Cefaxon when lidocaine solution is used as a solvent (see section 4.4). See information in the Summary of Product Characteristics of lidocaine, especially contraindications. Cefaxon solutions containing lidocaine should never be administered intravenously.

Hypersensitivity reactions

As with all beta-lactam antibacterial agents, serious and occasionally fatal hypersensitivity reactions have been reported (see section 4.8). In case of severe hypersensitivity reactions, treatment with Cefaxon must be discontinued immediately and adequate emergency measures must be initiated. Before beginning treatment, it should be established whether the patient has a history of severe hypersensitivity reactions to ceftriaxone, to other cephalosporins or to any other type of beta-lactam agent. Caution should be used if Cefaxon is given to patients with a history of non-severe hypersensitivity to other beta-lactam agents.

 

Severe cutaneous adverse reactions (Stevens Johnson syndrome or Lyell's syndrome/toxic epidermal necrolysis and drug reaction with eosinophilia and systemic symptoms (DRESS)) which can be life-threatening or fatal have been reported in association of ceftriaxone treatment; however, the frequency of these events is not known (see section 4.8).

 

Paediatric population

Safety and effectiveness of ceftriaxone in neonates, infants and children have been established for the dosages described under Posology and Method of Administration (see section 4.2). Studies have shown that ceftriaxone, like some other cephalosporins, can displace bilirubin from serum albumin.

 

Cefaxon is contraindicated in premature and full-term neonates at risk of developing bilirubin encephalopathy (see section 4.3).

 

Immune mediated haemolytic anaemia

An immune mediated haemolytic anaemia has been observed in patients receiving cephalosporin class antibacterials including ceftriaxone (see section 4.8). Severe cases of haemolytic anaemia, including fatalities, have been reported during ceftriaxone treatment in both adults and children.

 

If a patient develops anaemia while on Cefaxon, the diagnosis of a cephalosporin-associated anaemia should be considered and Cefaxon discontinued until the aetiology is determined.

 

Long term treatment

During prolonged treatment complete blood count should be performed at regular intervals.

 

Colitis/Overgrowth of non-susceptible microorganisms

Antibacterial agent-associated colitis and pseudo-membranous colitis have been reported with nearly all antibacterial agents, including ceftriaxone, and may range in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhoea during or subsequent to the administration of Cefaxon (see section 4.8). Discontinuation of therapy with Cefaxon and the administration of specific treatment for Clostridium difficile should be considered. Medicinal products that inhibit peristalsis should not be given.

 

Superinfections with non-susceptible micro-organisms may occur as with other antibacterial agents.

 

Severe renal and hepatic insufficiency

In severe renal and hepatic insufficiency, close clinical monitoring for safety and efficacy is advised (see section 4.2).

 

Interference with serological testing

Interference with Coombs tests may occur, as Cefaxon may lead to false-positive test results.

 

Cefaxon can also lead to false-positive test results for galactosaemia (see section 4.8).

 

Non-enzymatic methods for the glucose determination in urine may give false-positive results. Urine glucose determination during therapy with Cefaxon should be done enzymatically (see section 4.8).

 

The presence of ceftriaxone may falsely lower estimated blood glucose values obtained with some blood glucose monitoring systems. Please refer to instructions for use for each system. Alternative testing methods should be used if necessary.

 

Sodium

Cefaxon contains sodium. Each vial of Cefaxon 500 mg Powder for Solution for Injection contains 41.492 mg sodium (main component of cooking/table salt). This is equivalent to 2.1% of the recommended maximum daily dietary intake of sodium for an adult.

 

Antibacterial spectrum

Ceftriaxone has a limited spectrum of antibacterial activity and may not be suitable for use as a single agent for the treatment of some types of infections unless the pathogen has already been confirmed (see section 4.2). In polymicrobial infections, where suspected pathogens include organisms resistant to Cefaxon, administration of an additional antibiotic should be considered.

 

Use of lidocaine

In case a lidocaine solution is used as a solvent, Cefaxon solutions must only be used for intramuscular injection. Contraindications to lidocaine, warnings and other relevant information as detailed in the Summary of Product Characteristics of lidocaine must be considered before use (see section 4.3). The lidocaine solution should never be administered intravenously.

 

Biliary lithiasis

When shadows are observed on sonograms, consideration should be given to the possibility of precipitates of calcium-ceftriaxone. Shadows, which have been mistaken for gallstones, have been detected on sonograms of the gallbladder and have been observed more frequently at ceftriaxone doses of 1000 mg per day and above. Caution should be particularly considered in the paediatric population. Such precipitates disappear after discontinuation of ceftriaxone therapy. Rarely precipitates of calcium-ceftriaxone have been associated with symptoms. In symptomatic cases, conservative nonsurgical management is recommended and discontinuation of ceftriaxone treatment should be considered by the physician based on specific benefit risk assessment (see section 4.8).

 

Biliary stasis

Cases of pancreatitis, possibly of biliary obstruction aetiology, have been reported in patients treated with ceftriaxone (see section 4.8). Most patients presented with risk factors for biliary stasis and biliary sludge e.g. preceding major therapy, severe illness and total parenteral nutrition. A trigger or cofactor of ceftriaxone-related biliary precipitation cannot be ruled out.

 

Renal lithiasis

Cases of renal lithiasis have been reported, which is reversible upon discontinuation of ceftriaxone (see section 4.8). In symptomatic cases, sonography should be performed. Use in patients with history of renal lithiasis or with hypercalciuria should be considered by the physician based on specific benefit risk assessment.

 

Jarisch-Herxheimer reaction (JHR)

Some patients with spirochete infections may experience a Jarisch-Herxheimer reaction (JHR) shortly after ceftriaxone treatment is started. JHR is usually a self - limiting condition or can be managed by symptomatic treatment. The antibiotic treatment should not be discontinued if such reaction occurs.

 

Encephalopathy

Encephalopathy has been reported with the use of ceftriaxone (see section 4.8), particularly in elderly patients with severe renal impairment (see section 4.2) or central nervous system disorders. If ceftriaxone-associated encephalopathy is suspected (e.g. decreased level of consciousness, altered mental state, myoclonus, convulsions), discontinuation of Cefaxon should be considered.

Concomitant use with oral anticoagulants may increase the anti-vitamin K effect and the risk of bleeding. It is recommended that the International Normalised Ratio (INR) is monitored frequently and the posology of the anti-vitamin K drug adjusted accordingly, both during and after treatment with Cefaxon (see section 4.8).

 

There is conflicting evidence regarding a potential increase in renal toxicity of aminoglycosides when used with cephalosporins. The recommended monitoring of aminoglycoside levels (and renal function) in clinical practice should be closely adhered to in such cases.

 

In an in-vitro study antagonistic effects have been observed with the combination of chloramphenicol and ceftriaxone. The clinical relevance of this finding is unknown.

 

There have been no reports of an interaction between ceftriaxone and oral calcium-containing products or interaction between intramuscular ceftriaxone and calcium-containing products (intravenous or oral).

 

In patients treated with ceftriaxone, the Coombs' test may lead to false-positive test results.

 

Ceftriaxone, like other antibiotics, may result in false-positive tests for galactosaemia.

 

Likewise, non-enzymatic methods for glucose determination in urine may yield false-positive results. For this reason, glucose level determination in urine during therapy with Cefaxon should be carried out enzymatically.

 

No impairment of renal function has been observed after concurrent administration of large doses of ceftriaxone and potent diuretics (e.g. furosemide).

 

Simultaneous administration of probenecid does not reduce the elimination of ceftriaxone.

Pregnancy

Ceftriaxone crosses the placental barrier. There are limited amounts of data from the use of ceftriaxone in pregnant women. Animal studies do not indicate direct or indirect harmful effects with respect to embryonal/foetal, perinatal and postnatal development (see section 5.3). Ceftriaxone should only be administered during pregnancy and in particular in the first trimester of pregnancy if the benefit outweighs the risk.

 

Breastfeeding

Ceftriaxone is excreted into human milk in low concentrations but at therapeutic doses of ceftriaxone no effects on the breastfed infants are anticipated. However, a risk of diarrhoea and fungal infection of the mucous membranes cannot be excluded. The possibility of sensitisation should be taken into account. A decision must be made whether to discontinue breast-feeding or to discontinue/abstain from ceftriaxone therapy, taking into account the benefit of breast feeding for the child and the benefit of therapy for the woman.

 

Fertility

Reproductive studies have shown no evidence of adverse effects on male or female fertility.

During treatment with Cefaxon, undesirable effects may occur (e.g. dizziness), which may influence the ability to drive and use machines (see section 4.8). Patients should be cautious when driving or operating machinery.

 

The most frequently reported adverse reactions for ceftriaxone are eosinophilia, leucopenia, thrombocytopenia, diarrhoea, rash, and hepatic enzymes increased.

 

Data to determine the frequency of ceftriaxone ADRs was derived from clinical trials.

 

The following convention has been used for the classification of frequency:

Very common (≥ 1/10)

Common (≥ 1/100 - < 1/10)

Uncommon (≥ 1/1000 - < 1/100)

Rare (≥ 1/10000 - < 1/1000)

Not known (cannot be estimated from the available data)

 

System Organ Class	Common	Uncommon	Rare	Not Known a
Infections and infestations		Genital fungal infection	Pseudo-membranous colitisb	Superinfectionb
Blood and lymphatic system disorders	Eosinophilia Leucopenia Thrombocytopenia	Granulocytopenia Anaemia Coagulopathy		Haemolytic anaemiab Agranulocytosis
Immune system disorders				Anaphylactic shock Anaphylactic reaction Anaphylactoid reaction Hypersensitivityb Jarisch-Herxheimer reactionb
Nervous system disorders		Headache Dizziness	Encephalopathy	Convulsion
Ear and labyrinth disorders				Vertigo
Respiratory, thoracic and mediastinal disorders			Bronchospasm
Gastrointestinal disorders	Diarrhoeab Loose stools	Nausea Vomiting		Pancreatitisb Stomatitis Glossitis
Hepatobiliary disorders	Hepatic enzyme increased			Gall bladder precipitationb Kernicterus Hepatitisc Hepatitis cholestaticb,c
Skin and subcutaneous tissue disorders	Rash	Pruritus	Urticaria	Stevens Johnson Syndromeb Toxic epidermal necrolysisb Erythema multiforme Acute generalised exanthematous pustulosis Drug reaction with eosinophilia and systemic symptoms (DRESS)b
Renal and urinary disorders			Haematuria Glycosuria	Oliguria Renal precipitation (reversible)
General disorders and administration site conditions		Phlebitis Injection site reaction Pyrexia	Oedema Chills
Investigations		Blood creatinine increased		Coombs test false positiveb Galactosaemia test false positiveb Non enzymatic methods for glucose determination false positiveb

^a Based on post-marketing reports. Since these reactions are reported voluntarily from a population of uncertain size, it is not possible to reliably estimate their frequency which is therefore categorised as not known.

^b See section 4.4

c Usually reversible upon discontinuation of ceftriaxone

 

 

Description of selected adverse reactions

Infections and infestations

Reports of diarrhoea following the use of ceftriaxone may be associated with Clostridium difficile. Appropriate fluid and electrolyte management should be instituted (see section 4.4)

 

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via:

• Saudi Arabia

The National Pharmacovigilance Centre (NPC)

SFDA Call Center: 19999

E-mail: npc.drug@sfda.gov.sa

Website: https://ade.sfda.gov.sa

 

• Other GCC States

Please contact the relevant competent authority.

In overdose, the symptoms of nausea, vomiting and diarrhoea can occur. Ceftriaxone concentrations cannot be reduced by haemodialysis or peritoneal dialysis. There is no specific antidote. Treatment of overdose should be symptomatic.

Pharmacotherapeutic group: Antibacterials for systemic use, Third-generation cephalosporins, ATC code: J01DD04

 

Mode of action

Ceftriaxone inhibits bacterial cell wall synthesis following attachment to penicillin binding proteins (PBPs). This results in the interruption of cell wall (peptidoglycan) biosynthesis, which leads to bacterial cell lysis and death.

 

Resistance

Bacterial resistance to ceftriaxone may be due to one or more of the following mechanisms:

• Hydrolysis by beta-lactamases, including extended-spectrum beta-lactamases (ESBLs), carbapenemases and Amp C enzymes that may be induced or stably derepressed in certain aerobic Gram-negative bacterial species.
• Reduced affinity of penicillin-binding proteins for ceftriaxone.
• Outer membrane impermeability in Gram-negative organisms.
• Bacterial efflux pumps.

 

Susceptibility testing breakpoints

Minimum inhibitory concentration (MIC) breakpoints established by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) are as follows:

Pathogen	Dilution Test (MIC, mg/L)
	Susceptible	Resistant
Enterobacteriaceae	≤ 1	> 2
Staphylococcus spp.	a.	a.
Streptococcus spp. (Groups A, B, C and G)	b.	b.
Streptococcus pneumoniae	≤ 0.5c.	> 2
Viridans group Streptococci	≤0.5	>0.5
Haemophilus influenzae	≤ 0.12c.	> 0.12
Moraxella catarrhalis	≤ 1	> 2
Neisseria gonorrhoeae	≤ 0.12	> 0.12
Neisseria meningitidis	≤ 0.12 c.	> 0.12
Non-species related	≤ 1d.	> 2

a. Susceptibility inferred from cefoxitin susceptibility.

b. Susceptibility inferred from penicillin susceptibility.

c. Isolates with a ceftriaxone MIC above the susceptible breakpoint are rare and, if found, should be re-tested and, if confirmed, should be sent to a reference laboratory.

d. Breakpoints apply to a daily intravenous dose of 1000 mg x 1 and a high dose of at least 2000 mg x 1.

 

Clinical efficacy against specific pathogens

The prevalence of acquired resistance may vary geographically and with time for selected species and local information on resistance is desirable, particularly when treating severe infections. As necessary, expert advice should be sought when the local prevalence of resistance is such that the utility of ceftriaxone in at least some types of infections is questionable.

Commonly susceptible species

Gram-positive aerobes Staphylococcus aureus (methicillin-susceptible)£ Staphylococci coagulase-negative (methicillin-susceptible)£ Streptococcus pyogenes (Group A) Streptococcus agalactiae (Group B) Streptococcus pneumoniae Viridans Group Streptococci Gram-negative aerobes Borrelia burgdorferi Haemophilus influenzae Haemophilus parainfluenzae Moraxella catarrhalis Neisseria gonorrhoea Neisseria meningitidis Proteus mirabilis Providencia spp. Treponema pallidum

Species for which acquired resistance may be a problem

Gram-positive aerobes Staphylococcus epidermidis+ Staphylococcus haemolyticus+ Staphylococcus hominis+ Gram-negative aerobes Citrobacter freundii Enterobacter aerogenes Enterobacter cloacae Escherichia coli% Klebsiella pneumoniae% Klebsiella oxytoca% Morganella morganii Proteus vulgaris Serratia marcescens Anaerobes Bacteroides spp. Fusobacterium spp. Peptostreptococcus spp. Clostridium perfringens

Inherently resistant organisms

Gram-positive aerobes Enterococcus spp. Listeria monocytogenes Gram-negative aerobes Acinetobacter baumannii Pseudomonas aeruginosa Stenotrophomonas maltophilia Anaerobes Clostridium difficile Others: Chlamydia spp. Chlamydophila spp. Mycoplasma spp. Legionella spp. Ureaplasma urealyticum

£ All methicillin-resistant staphylococci are resistant to ceftriaxone.

⁺ Resistance rates >50% in at least one region

^% ESBL producing strains are always resistant

Absorption

Intramuscular administration

Following intramuscular injection, mean peak plasma ceftriaxone levels are approximately half those observed after intravenous administration of an equivalent dose. The maximum plasma concentration after a single intramuscular dose of 1000 mg is about 81 mg/l and is reached in 2 - 3 hours after administration.

 

The area under the plasma concentration-time curve after intramuscular administration is equivalent to that after intravenous administration of an equivalent dose.

 

Distribution

The volume of distribution of ceftriaxone is 7 – 12 l. Concentrations well above the minimal inhibitory concentrations of most relevant pathogens are detectable in tissue including lung, heart, biliary tract/liver, tonsil, middle ear and nasal mucosa, bone, and in cerebrospinal, pleural, prostatic and synovial fluids. An 8 - 15% increase in mean peak plasma concentration (C_max) is seen on repeated administration; steady state is reached in most cases within 48 - 72 hours depending on the route of administration.

 

Penetration into particular tissues

Ceftriaxone penetrates the meninges. Penetration is greatest when the meninges are inflamed. Mean peak ceftriaxone concentrations in CSF in patients with bacterial meningitis are reported to be up to 25% of plasma levels compared to 2% of plasma levels in patients with uninflamed meninges.  Peak ceftriaxone concentrations in CSF are reached approximately 4-6 hours after intravenous injection. Ceftriaxone crosses the placental barrier and is excreted in the breast milk at low concentrations (see section 4.6).

 

Protein binding

Ceftriaxone is reversibly bound to albumin. Plasma protein binding is about 95 % at plasma concentrations below 100 mg/l. Binding is saturable and the bound portion decreases with rising concentration (up to 85% at a plasma concentration of 300 mg/l).

 

Biotransformation

Ceftriaxone is not metabolised systemically; but is converted to inactive metabolites by the gut flora.

 

Elimination

Plasma clearance of total ceftriaxone (bound and unbound) is 10 - 22 ml/min. Renal clearance is 5 - 12 ml/min. 50 - 60% of ceftriaxone is excreted unchanged in the urine, primarily by glomerular filtration, while 40 - 50% is excreted unchanged in the bile. The elimination half-life of total ceftriaxone in adults is about 8 hours.

 

Patients with renal or hepatic impairment

In patients with renal or hepatic dysfunction, the pharmacokinetics of ceftriaxone are only minimally altered with the half-life slightly increased (less than two fold), even in patients with severely impaired renal function.

 

The relatively modest increase in half-life in renal impairment is explained by a compensatory increase in non-renal clearance, resulting from a decrease in protein binding and corresponding increase in non-renal clearance of total ceftriaxone.

 

In patients with hepatic impairment, the elimination half-life of ceftriaxone is not increased, due to a compensatory increase in renal clearance. This is also due to an increase in plasma free fraction of ceftriaxone contributing to the observed paradoxical increase in total drug clearance, with an increase in volume of distribution paralleling that of total clearance.

 

Older people

In older people aged over 75 years the average elimination half-life is usually two to three times that of young adults.

 

Paediatric population

The half-life of ceftriaxone is prolonged in neonates. From birth to 14 days of age, the levels of free ceftriaxone may be further increased by factors such as reduced glomerular filtration and altered protein binding. During childhood, the half-life is lower than in neonates or adults.

 

The plasma clearance and volume of distribution of total ceftriaxone are greater in neonates, infants and children than in adults.

 

Linearity/non-linearity

The pharmacokinetics of ceftriaxone are non-linear and all basic pharmacokinetic parameters, except the elimination half-life, are dose dependent if based on total drug concentrations, increasing less than proportionally with dose. Non-linearity is due to saturation of plasma protein binding and is therefore observed for total plasma ceftriaxone but not for free (unbound) ceftriaxone.

 

Pharmacokinetic/pharmacodynamic relationship

As with other beta-lactams, the pharmacokinetic-pharmacodynamic index demonstrating the best correlation with in vivo efficacy is the percentage of the dosing interval that the unbound concentration remains above the minimum inhibitory concentration (MIC) of ceftriaxone for individual target species (i.e. %T > MIC).

There is evidence from animal studies that high doses of ceftriaxone calcium salt led to formation of concrements and precipitates in the gallbladder of dogs and monkeys, which proved to be reversible. Animal studies produced no evidence of toxicity to reproduction and genotoxicity. Carcinogenicity studies on ceftriaxone were not conducted.

 

There are no other ingredients.

Based on literature reports, ceftriaxone is not compatible with amsacrine, vancomycin, fluconazole and aminoglycosides.

 

If treatment with a combination of another antibiotic with Cefaxon is intended, administration should not occur in the same syringe or in the same infusion solution.

 

This medicinal product must not be mixed with other medicinal products except those mentioned in section 6.6.

Unopened vials: 36 months. Chemical and physical in-use stability of the reconstituted product and diluted solution has been demonstrated for at least 6 hours at or below 25°C or 24 hours at 2-8°C. From a microbiological point of view, the product should be used immediately. If not used immediately, in-use storage times and conditions prior to use are the responsibility of the user and would not be longer than the times stated above for the chemical and physical in-use stability.

Store below 25°C.

 

Store in the original package in order to protect from light.

 

For storage conditions of the reconstituted medicinal product, see section 6.3.

Colorless sealed vials with royal blue caps.

 

Pack size: 1 Vial and 1 Solvent ampoule (5 ml of 1% lidocaine HCl).

Preparation of solutions for injection

The use of freshly prepared solutions is recommended. For storage conditions of the reconstituted medicinal product, see section 6.3.

 

Cefaxon should not be mixed in the same syringe with any drug other than 1% lidocaine HCl solution (for intramuscular injection only).

 

Cefaxon 500 mg Powder for Solution for Injection

For IM injection 500 mg Cefaxon is dissolved in 2 ml of 1% lidocaine HCl solution. The solution should be administered by deep intramuscular injection. Dosages greater than 1000 mg should be divided and injected at more than one site.

 

The displacement volume of 500 mg of Cefaxon is 0.36 ml in 1% lidocaine HCl solution. When adding 2 ml of 1% lidocaine HCl solution, the final concentration of the reconstituted solution is 211.86 mg/ml.

 

Any unused product or waste material should be disposed of in accordance with local requirements.